Myocardial ischemia during mental stress: role of coronary artery disease burden and vasomotion

Sex Differences in Mental Stress-Induced Myocardial Ischemia in Patients With Coronary Heart Disease

BACKGROUND

Emerging data suggest that young women with coronary heart disease (CHD) are disproportionally vulnerable to the adverse cardiovascular effects of psychological stress. We hypothesized that younger, but not older, women with stable CHD are more likely than their male peers to develop mental stress-induced myocardial ischemia (MSIMI).

METHODS AND RESULTS

We studied 686 patients (191 women) with stable coronary heart disease (CHD). Patients underwent (99m)Tc-sestamibi myocardial perfusion imaging at rest and with both mental (speech task) and conventional (exercise/pharmacological) stress testing. We compared quantitative (by automated software) and visual parameters of inducible ischemia between women and men and assessed age as an effect modifier. Women had a more-adverse psychosocial profile than men whereas there were few differences in medical history and CHD risk factors. Both quantitative and visual indicators of ischemia with mental stress were disproportionally larger in younger women. For each 10 years of decreasing age, the total reversibility severity score with mental stress was 9.6 incremental points higher (interaction, P<0.001) and the incidence of MSIMI was 82.6% higher (interaction, P=0.004) in women than in men. Incidence of MSIMI in women ≤50 years was almost 4-fold higher than in men of similar age and older patients. These results persisted when adjusting for sociodemographic and medical risk factors, psychosocial factors, and medications. There were no significant sex differences in inducible ischemia with conventional stress.

CONCLUSIONS

Young women with stable CHD are susceptible to MSIMI, which could play a role in the prognosis of this group.

Behavioral, emotional and neurobiological determinants of coronary heart disease risk in women

Women have more of the stress-related behavioral profile that has been linked to cardiovascular disease than men. For example, women double the rates of stress-related mental disorders such as depression and posttraumatic stress disorder (PTSD) than men, and have higher rates of exposure to adversity early in life. This profile may increase women's long-term risk of cardiometabolic conditions linked to stress, especially coronary heart disease (CHD). In addition to having a higher prevalence of psychosocial stressors, women may be more vulnerable to the adverse effects of these stressors on CHD, perhaps through altered neurobiological physiology. Emerging data suggest that young women are disproportionally susceptible to the adverse effects of stress on the risk of cardiovascular disease, both in terms of initiating the disease as well as worsening the prognosis in women who have already exhibited symptoms of the disease. Women's potential vulnerability to psychosocial stress could also help explain their higher propensity toward abnormal coronary vasomotion and microvascular disease compared with men.

Emotional triggering of cardiac dysfunction: the present and future

Mental stress and emotional arousal can act as triggers of acute myocardial infarction and other adverse cardiovascular outcomes. Experimental research examining mechanisms of the adverse interplay between mind and heart has led to the discovery of mental stress-induced cardiac dysfunction or myocardial ischemia (MSIMI). Evidence about the prevalence, clinical significance, and mechanistic bases of MSIMI outlines a wide range of central and peripheral bio-pathologic processes that are associated with emotions and behaviors. MSIMI is recognized as an integrated and intermediate biomarker underpinning the negative mind-heart interplay. Particularly, MSIMI research paves the way toward investigations aiming more specifically at recognizing the susceptibilities of individuals who are prone to respond adversely to the psycho-social-environmental stress. This article reviews recent literature on MSIMI research following the comprehensive review of Strike and Steptoe Eur Heart J 24:690-703, 2003. Further, this article outlines the main steps in the identification of the specific bio-pathologic manifestations of the cardiovascular system to emotional stress. Finally, a speculative description is provided of future directions in better searching for areas that may be critical targets in resolving adverse mind-heart interplays.

The Role of the Myocardial Microvasculature in Mental Stress-Induced Myocardial Ischemia

There is increasing evidence that mental stress can manifest as physical diseases. One such condition is mental stress-induced myocardial ischemia (MSIMI); a silent, transient, myocardial ischemic response to stressful conditions. We propose that the cardiac microvasculature may be an important site for the interplay between mental stress and MSIMI. This study is a review of the literature discussing the prevalence and emerging mechanisms underlying MSIMI. We identified several aspects underlying MSIMI, including psychological, genetic, and physiological causes. Several sources suggested that dysfunctional cardiac microvasculature might be a contributing factor in the development of stress-induced myocardial ischemia. The literature also suggested that although MSIMI has distinct features and pathophysiology, its occurrence might indicate an increased future risk of cardiovascular events. We found that dysfunctional cardiac microvasculature may be the key point of interaction between mental stress and transient myocardial ischemia and that the development of MSIMI might be a "silent" indicator for future cardiac events.

Panic disorder and incident coronary heart disease: a systematic review and meta-regression in 1131612 persons and 58111 cardiac events

BACKGROUND

Substantial healthcare resources are devoted to panic disorder (PD) and coronary heart disease (CHD); however, the association between these conditions remains controversial. Our objective was to conduct a systematic review of studies assessing the association between PD, related syndromes, and incident CHD.

METHOD

Relevant studies were retrieved from Medline, EMBASE, SCOPUS and PsycINFO without restrictions from inception to January 2015 supplemented with hand-searching. We included studies that reported hazard ratios (HR) or sufficient data to calculate the risk ratio and 95% confidence interval (CI) which were pooled using a random-effects model. Studies utilizing self-reported CHD were ineligible. Twelve studies were included comprising 1 131 612 persons and 58 111 incident CHD cases.

RESULTS

PD was associated with the primary incident CHD endpoint [adjusted HR (aHR) 1.47, 95% CI 1.24-1.74, p < 0.00001] even after excluding angina (aHR 1.49, 95% CI 1.22-1.81, p < 0.00001). High to moderate quality evidence suggested an association with incident major adverse cardiac events (MACE; aHR 1.40, 95% CI 1.16-1.69, p = 0.0004) and myocardial infarction (aHR 1.36, 95% CI 1.12-1.66, p = 0.002). The risk for CHD was significant after excluding depression (aHR 1.64, 95% CI 1.45-1.85) and after depression adjustment (aHR 1.38, 95% CI 1.03-1.87). Age, sex, length of follow-up, socioeconomic status and diabetes were sources of heterogeneity in the primary endpoint.

CONCLUSIONS

Meta-analysis showed that PD was independently associated with incident CHD, myocardial infarction and MACE; however, reverse causality cannot be ruled out and there was evidence of heterogeneity.

Angina and mental stress-induced myocardial ischemia

OBJECTIVE

Mental stress-induced myocardial ischemia is a common phenomenon in patients with coronary artery disease (CAD) and an emerging prognostic factor. Mental stress ischemia is correlated with ambulatory ischemia. However, whether it is related to angina symptoms during daily life has not been examined.

METHODS

We assessed angina frequency (past month) in 98 post-myocardial infarction (MI) subjects (age 18-60 years) using the Seattle Angina Questionnaire. Patients underwent [(99m)Tc]sestamibi SPECT perfusion imaging at rest, after mental stress, and after exercise/pharmacological stress. Summed scores of perfusion abnormalities were obtained by observer-independent software. A summed difference score (SDS), the difference between stress and rest scores, was used to quantify myocardial ischemia under both stress conditions.

RESULTS

The mean age was 50 years, 50% were female and 60% were non-white. After adjustment for age, sex, smoking, CAD severity, depressive, anger, and anxiety symptoms, each 1-point increase in mental stress-SDS was associated with 1.73-unit increase in the angina frequency score (95% CI: 0.09-3.37) and 17% higher odds of being in a higher angina frequency category (OR: 1.17, 95% CI: 1.00-1.38). Depressive symptoms were associated with 12% higher odds of being in a higher angina frequency category (OR: 1.12, 95% CI: 1.03-1.21). In contrast, exercise/pharmacological stress-induced SDS was not associated with angina frequency.

CONCLUSION

Among young and middle-aged post-MI patients, myocardial ischemia induced by mental stress in the lab, but not by exercise/pharmacological stress, is associated with higher frequency of retrospectively reported angina during the day. Psychosocial stressors related to mental stress ischemia may be important contributory factor to daily angina.

Association between anger and mental stress-induced myocardial ischemia

BACKGROUND

Mental stress-induced myocardial ischemia is associated with adverse prognosis in coronary artery disease patients. Anger is thought to be a trigger of acute coronary syndromes and is associated with increased cardiovascular risk; however, little direct evidence exists for a link between anger and myocardial ischemia.

METHODS

[(99m)Tc]-sestamibi single-photon emission tomography was performed at rest, after mental stress (a social stressor with a speech task) and after exercise/pharmacologic stress. Summed scores of perfusion abnormalities were obtained by observer-independent software. A summed-difference score, the difference between stress and rest scores, was used to quantify myocardial ischemia under both stress conditions. The Spielberger's State-Trait Anger Expression Inventory was used to assess different anger dimensions.

RESULTS

The mean age was 50 years, 50% were female, and 60% were non-white. After adjusting for demographic factors, smoking, coronary artery disease severity, depressive, and anxiety symptoms, each IQR increment in state-anger score was associated with 0.36 U-adjusted increase in ischemia as measured by the summed-difference score (95% CI 0.14-0.59); the corresponding association for trait anger was 0.95 (95% CI 0.21-1.69). Anger expression scales were not associated with ischemia. None of the anger dimensions was related to ischemia during exercise/pharmacologic stress.

CONCLUSION

Anger, both as an emotional state and as a personality trait, is significantly associated with propensity to develop myocardial ischemia during mental stress but not during exercise/pharmacologic stress. Patients with this psychologic profile may be at increased risk for silent ischemia induced by emotional stress, and this may translate into worse prognosis.

Depressive symptoms are associated with mental stress-induced myocardial ischemia after acute myocardial infarction

OBJECTIVES

Depression is an adverse prognostic factor after an acute myocardial infarction (MI), and an increased propensity toward emotionally-driven myocardial ischemia may play a role. We aimed to examine the association between depressive symptoms and mental stress-induced myocardial ischemia in young survivors of an MI.

METHODS

We studied 98 patients (49 women and 49 men) age 38-60 years who were hospitalized for acute MI in the previous 6 months. Patients underwent myocardial perfusion imaging at rest, after mental stress (speech task), and after exercise or pharmacological stress. A summed difference score (SDS), obtained with observer-independent software, was used to quantify myocardial ischemia under both stress conditions. The Beck Depression Inventory-II (BDI-II) was used to measure depressive symptoms, which were analyzed as overall score, and as separate somatic and cognitive depressive symptom scores.

RESULTS

There was a significant positive association between depressive symptoms and SDS with mental stress, denoting more ischemia. After adjustment for demographic and lifestyle factors, disease severity and medications, each incremental depressive symptom was associated with 0.14 points higher SDS. When somatic and cognitive depressive symptoms were examined separately, both somatic [β = 0.17, 95% CI: (0.04, 0.30), p = 0.01] and cognitive symptoms [β = 0.31, 95% CI: (0.07, 0.56), p = 0.01] were significantly associated with mental stress-induced ischemia. Depressive symptoms were not associated with ischemia induced by exercise or pharmacological stress.

CONCLUSION

Among young post-MI patients, higher levels of both cognitive and somatic depressive symptoms are associated with a higher propensity to develop myocardial ischemia with mental stress, but not with physical (exercise or pharmacological) stress.

Meta-analysis of mental stress-induced myocardial ischemia and subsequent cardiac events in patients with coronary artery disease

Mental stress-induced myocardial ischemia (MSIMI) has been associated with adverse prognosis in patients with coronary artery disease (CAD), but whether this is a uniform finding across different studies has not been described. We conducted a systematic review and meta-analysis of prospective studies examining the association between MSIMI and adverse outcome events in patients with stable CAD. We searched PubMed, EMBASE, Web of Science, and PsycINFO databases for English language prospective studies of patients with CAD who underwent standardized mental stress testing to determine presence of MSIMI and were followed up for subsequent cardiac events or total mortality. Our outcomes of interest were CAD recurrence, CAD mortality, or total mortality. A summary effect estimate was derived using a fixed-effects meta-analysis model. Only 5 studies, each with a sample size of <200 patients and fewer than 50 outcome events, met the inclusion criteria. The pooled samples comprised 555 patients with CAD (85% male) and 117 events with a range of follow-up from 35 days to 8.8 years. Pooled analysis showed that MSIMI was associated with a twofold increased risk of a combined end point of cardiac events or total mortality (relative risk 2.24, 95% confidence interval 1.59 to 3.15). No heterogeneity was detected among the studies (Q=0.39, I2=0.0%, p=0.98). In conclusion, although few selected studies have examined the association between MSIMI and adverse events in patients with CAD, all existing investigations point to approximately a doubling of risk. Whether this increased risk is generalizable to the CAD population at large and varies in patient subgroups warrant further investigation.

Sex differences in mental stress-induced myocardial ischemia in young survivors of an acute myocardial infarction

OBJECTIVES

Emotional stress may disproportionally affect young women with ischemic heart disease. We sought to examine whether mental stress-induced myocardial ischemia (MSIMI), but not exercise-induced ischemia, is more common in young women with previous myocardial infarction (MI) than in men.

METHODS

We studied 98 post-MI patients (49 women and 49 men) aged 38 to 60 years. Women and men were matched for age, MI type, and months since MI. Patients underwent technetium-99m sestamibi perfusion imaging at rest, after mental stress, and after exercise/pharmacological stress. Perfusion defect scores were obtained with observer-independent software. A summed difference score (SDS), the difference between stress and rest scores, was used to quantify ischemia under both stress conditions.

RESULTS

Women 50 years or younger, but not older women, showed a more adverse psychosocial profile than did age-matched men but did not differ for conventional risk factors and tended to have less angiographic coronary artery disease. Compared with age-matched men, women 50 years or younger exhibited a higher SDS with mental stress (3.1 versus 1.5, p = .029) and had twice the rate of MSIMI (SDS ≥ 3; 52% versus 25%), whereas ischemia with physical stress did not differ (36% versus 25%). In older patients, there were no sex differences in MSIMI. The higher prevalence of MSIMI in young women persisted when adjusting for sociodemographic and life-style factors, coronary artery disease severity, and depression.

CONCLUSIONS

MSIMI post-MI is more common in women 50 years or younger compared with age-matched men. These sex differences are not observed in post-MI patients who are older than 50 years.